# =================================================================
#
# Part 1: Prerequisite Build Stages
#
# These stages are used as building blocks for the final images.
# They prepare the Rust binary and other resources.
#
# =================================================================

# -----------------------------------------------------------------
# Stage 0: Fetch static FFmpeg binaries
# -----------------------------------------------------------------
# We use a static build to ensure it works in the scratch image without libraries
# Static ffmpeg image is multi-arch, so it pulls correct arch automatically
FROM mwader/static-ffmpeg:7.1 AS ffmpeg-static

# -----------------------------------------------------------------
# Stage 1: Build the Rust binary for production
# -----------------------------------------------------------------
FROM ghcr.io/cross-rs/x86_64-unknown-linux-musl:main AS rust-build

# Get target architecture
ARG RUST_TARGET

RUN apt-get update && apt-get install -y --no-install-recommends pkg-config musl-tools libssl-dev

# Update Rust toolchain and add necessary target
RUN rustup update && rustup target add $RUST_TARGET

# Set Rust compiler flags for better optimization and reproducibility
ENV RUSTFLAGS='--remap-path-prefix $HOME=~ -C target-feature=+crt-static'

# Copy dependency files first for better layer caching
WORKDIR /src
COPY Cargo.toml Cargo.lock ./
COPY backend/Cargo.toml ./backend/
COPY frontend/Cargo.toml ./frontend/
COPY shared/Cargo.toml ./shared/

# Create dummy source files to build dependencies only
RUN mkdir -p src backend/src frontend/src shared/src && \
    echo "fn main() {}" > src/main.rs && \
    echo "fn main() {}" > backend/src/main.rs && \
    echo "fn main() {}" > frontend/src/main.rs && \
    echo "pub fn dummy() {}" > shared/src/lib.rs

# Build dependencies (this layer will be cached unless dependencies change)
RUN cargo build -p tuliprox --target $RUST_TARGET --release || true
RUN cargo build -p shared --target $RUST_TARGET --release || true

# Now copy the actual source code and build the project
COPY . .

RUN cargo build -p tuliprox --target $RUST_TARGET --release

# -----------------------------------------------------------------
# Stage 2: Build the rust frontend
# -----------------------------------------------------------------
FROM ghcr.io/cross-rs/x86_64-unknown-linux-musl:main AS trunk-build

ARG RUST_TARGET=wasm32-unknown-unknown

# Set working directory
WORKDIR /src

# Install dependencies for Trunk and WebAssembly
RUN apt-get update && apt-get install -y --no-install-recommends \
  pkg-config libssl-dev curl libclang-dev binaryen

# Add wasm target & install trunk
RUN rustup target add wasm32-unknown-unknown
RUN cargo install --locked trunk wasm-bindgen-cli

# Copy dependency files first for better layer caching
COPY Cargo.toml Cargo.lock ./
COPY frontend/Cargo.toml frontend/Trunk.toml ./frontend/
COPY shared/Cargo.toml ./shared/

# Create dummy source files
RUN mkdir -p frontend/src shared/src && \
    echo "fn main() {}" > frontend/src/main.rs && \
    echo "pub fn dummy() {}" > shared/src/lib.rs

# Pre-build dependencies
WORKDIR /src/frontend
RUN cargo build --target wasm32-unknown-unknown --release || true

# Now copy the actual source code and build the project
WORKDIR /src
COPY . .

WORKDIR /src/frontend

# Run Trunk build
RUN trunk build --release

# -----------------------------------------------------------------
# Stage 3: Build video resources with ffmpeg
# -----------------------------------------------------------------
FROM linuxserver/ffmpeg:latest AS resource-build

WORKDIR /src
COPY resources ./resources

# Combine ffmpeg commands into a single layer to reduce image size
# Convert every .jpg file in resources into a matching .ts file.
RUN set -eu; \
    find ./resources -maxdepth 1 -type f -name '*.jpg' | sort | while IFS= read -r image; do \
      output="${image%.jpg}.ts"; \
      ffmpeg -y -nostdin -loop 1 -framerate 30 -i "${image}" \
            -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=48000 \
            -t 10 -shortest \
            -c:v libx264 -pix_fmt yuv420p -preset veryfast -crf 23 \
            -x264-params "keyint=30:min-keyint=30:scenecut=0:bframes=0:open_gop=0" \
            -c:a aac -b:a 128k -ac 2 -ar 48000 \
            -mpegts_flags +resend_headers \
            -muxdelay 0 -muxpreload 0 \
            -f mpegts "${output}" || exit 1; \
    done

# -----------------------------------------------------------------
# Stage 4: Prepare timezone data
# -----------------------------------------------------------------
FROM alpine:latest AS tz-prep

ARG TZ=UTC
ENV TZ=${TZ}

RUN apk add --no-cache tzdata \
  && mkdir -p /output/etc \
  && mkdir -p /output/usr/share \
  && cp -r /usr/share/zoneinfo /output/usr/share/zoneinfo \
  && ln -sf /usr/share/zoneinfo/${TZ} /output/etc/localtime


# =================================================================
#
# Part 2: Final Image Stages
#
# These stages build the final, runnable images by assembling
# the artifacts from the prerequisite stages above.
#
# =================================================================

# -----------------------------------------------------------------
# Final Image #1: Debugging Environment (Alpine-based)
# -----------------------------------------------------------------
FROM rust:alpine AS debug

# For Alpine, the correct target architecture uses 'musl'
ARG RUST_TARGET=x86_64-unknown-linux-musl
ARG TZ=UTC

# Make the build-time argument available as a run-time environment variable
ENV RUST_TARGET=${RUST_TARGET}
ENV TZ=${TZ}

# Install build dependencies and the lldb debugger for Alpine
# Added 'perl' which is required to build the native OpenSSL library.
# Added ffmpeg for probing
RUN apk add --no-cache bash build-base openssl-dev lldb gdb perl ffmpeg

# Update Rust toolchain and add the necessary target
RUN rustup update && rustup target add $RUST_TARGET

# Create the final application layout to mimic production
WORKDIR /app
COPY --from=trunk-build /src/frontend/dist ./web
COPY --from=resource-build /src/resources ./resources

# Create a separate directory for the source code
WORKDIR /usr/src/tuliprox
COPY . .

# Copy the entrypoint script and set it as the entrypoint for the container.
COPY ./docker/debug/debug-entrypoint.sh /usr/local/bin/entrypoint.sh
# Ensure the script is executable
RUN chmod +x /usr/local/bin/entrypoint.sh
ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]

# The CMD will be passed as arguments to the entrypoint script.
CMD ["tail", "-f", "/dev/null"]

# -----------------------------------------------------------------
# Final Image #2: Production image based on scratch
# -----------------------------------------------------------------
FROM scratch AS scratch-final

ARG RUST_TARGET

# Copy timezone data and localtime from tz-prep
COPY --from=tz-prep /output/usr/share/zoneinfo /usr/share/zoneinfo
COPY --from=tz-prep /output/etc/localtime /etc/localtime

# Certificates
COPY --from=rust-build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/

# Copy static ffmpeg/ffprobe binaries
COPY --from=ffmpeg-static /ffmpeg /usr/local/bin/
COPY --from=ffmpeg-static /ffprobe /usr/local/bin/

# RUN ln -sf /usr/share/zoneinfo/${TZ} /etc/localtime

# App
WORKDIR /app
COPY --from=rust-build /src/target/${RUST_TARGET}/release/tuliprox ./tuliprox
COPY --from=trunk-build /src/frontend/dist ./web
COPY --from=resource-build /src/resources ./resources

ENTRYPOINT ["/app/tuliprox"]
CMD ["-s", "-p", "/app/config"]

# -----------------------------------------------------------------
# Final Image #3: Production image based on Alpine
# -----------------------------------------------------------------
FROM alpine:latest AS alpine-final

ARG RUST_TARGET
ARG TZ=UTC
ENV TZ=${TZ}

# Install dependencies including ffmpeg
RUN apk add --no-cache bash curl ca-certificates tini ffmpeg

COPY --from=rust-build /usr/share/zoneinfo /usr/share/zoneinfo
COPY --from=rust-build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/

# Default timezone fallback
RUN ln -sf /usr/share/zoneinfo/${TZ} /etc/localtime

WORKDIR /app
COPY --from=rust-build /src/target/${RUST_TARGET}/release/tuliprox ./tuliprox
COPY --from=trunk-build /src/frontend/dist ./web
COPY --from=resource-build /src/resources ./resources

ENTRYPOINT ["/sbin/tini", "--", "/app/tuliprox"]
CMD ["-s", "-p", "/app/config"]
